Boring device.



. COBB.

BORING DEVICE.

APPLICATION FILED JULY 24, 1905 Patented .Nov. 22, 19-10.

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E. M. COBB. BORING DEVICE.

APPLICATION FILED JULY 24, 1905 Patented Nov. 22, 1910.

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E. M. COBB.

BORING DEVICE.

APPLIOATION FILED JULY 24, 1905 Patented Nov.22, 1910.

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Inventor.

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UNTED STATES PATENT OFFICE.

ELMER IVI. COBB, OF SOUTH PORTLAND, MAINE, ASSIGNOR TO LANG-COBB MANU- FACTURING COMPANY, OF PORTLAND, MAINE, A CORPORATION OF MAINE.

BORING DEVICE.

Specification of Letters Patent.

Patented Nov. 22, 1910.

Application filed July 24, 1905. Serial No. 270,970.

To all whom it may concern:

Be it known that I, ELMER M. COBB, a citizen of the United States, residing at South Portland, in the County of Cumberland and State of Maine, have invented an Improved Boring Device; and I hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in boring devices, and it consists in an improved device whereby by the use of an ordinary it and an ordinary brace, or other power, holes may be bored in positions and places where an ordinary bit could not be used alone by reason of intervening obstacles.

The object of my invention is to provide a simple and easily operated boring device by means of which holes may be bored in corners, either horizontal or inclined, or be tween joists and in other places ditficult of access.

With this object in view, my invention consists in the construction and combinations of parts as hereinafter described and claimed.

In the accompanying drawingsFigure 1 is a perspective view of my invention, the brace not being shown. Fig. 2 is a vertical transverse section of said device, parts being shown in elevation. Fig. 3 is a top plan view of the spindle. Fig. 4; is a vertical transverse section of the feed nut. Fig. 5 is a similar section, showing the parts of the nut in a different position. Fig. 6 is a horizontal cross section of the spindle and collet on the line 00-00 of Fig. 2. Fig. 7 is a vertical section, showing the collet and the related parts. Fig. 8 is a side view of the spindle. Fig. 9 is a top plan view of the feed nut, the parts being in the position shown in Fig. A. Fig. lO'is a bottom plan view of the feed nut, the parts being in the position shown in Fig. 5. Fig. 11 is a side elevation, partly in section, showing a modified form of the supporting frame. Fig. 12 is a side view showing the device in position to bore a hole.

A represents the supporting frame, having inclined legs terminating in pointed portions 9. These legs are preferably united together by means of a ring 6 in order to give stifi'ness to the frame, but this ring is not strictly necessary. The frame is also provided with a ring or sleeve 6, located near its center, from which ring extend upwardly bent arms 0, terminating at their upper extremities in a ring 0 One of the arms 0 is provided with a centrally perforated boss 6, through which passes the spindle a, having a tapered polygonal end Q) of the usual shape for engaging with the brace.

Above the ring 0 the frame is provided with a hollow cylindrical extension d threaded on the outside.

7 represents an adjusting sleeve, closed at the upper end and threaded to engage with the threads on the outside of the part (Z. It is preferably knurled on the outside, as shown, and provided at its upper end with a central pointed projecting boss 9.

Within the body (Z, and passing through the rings 79, Z9 and c and gear wheel 1', is a hollow spindle h, shown detached in Fig. 8, and provided with a spline way 8. About half of the outside of the spindle h is screwthreaded and the other half smooth, as shown in Fig. 8, the smooth portions alternating with the threaded portions, and the spline way 8 being centrally located in one of the smooth portions. The inside of the hollow spindle in is perfectly smooth, except that it is provided with. oppositely arranged spline ways m.

Within the hollow spindle h, the collet or follower is adapted to slide freely, but is prevented from rotation by the splines Z thereon, which engage the spline ways we in the interior of the spindle. The collet j is normally forced out-ward by the spring 2', said spring at the upper end bearing against a head or nut 7, which is screwed into the upper hollow end of the spindle, or secured therein in any desired manner.

The lower end of the spindle h is expanded as shown at f, forming a cylindrical head, screw-threaded on the outside as shown in Fig. 8. Within this head are pivotally mounted two dogs 0, which play freely in slots at in said head. Arranged to screw onto the head f is a chuck 7), the lower end of which inclines inwardly, as shown in' Fig. 2, so that as it is screwed up along the head 7 it will force the dogs 0 inwardly, thus firmly holding the bit. The

lower end of the sleeve is perforated for the passage of the bit 9, of ordinary construction, one end thereof being tapered and made polygonal to engage a similar opening in the collet j, in the usual manner.

Mounted in the sleeve 1) is an annular beveled gear wheel a", by means of which the spindle h is driven and fed, as hereinafter described. I

1) indicates the spline carried by the gear wheel 1", which engages with the spline way 8 in the spindle h. r meshes witha beveled gear wheel t, secured 'to the spindle u, and it is confined on said spindle between the part 0 of the frame and the nut to, which is screwed onto the inner end of said spindle, as shown in Fig. 2. The nut w is provided with a pin a for a purpose hereinafter mentioned.

' Surrounding the spindle it, between the rings 1) and 0 is the feed nut, by means of which the .bit 9 is fed at intervals, and

I which may be so shifted as to allow a quick return. This nut, as shown in Figs. 2,4:, and 5, is a two-part nut. The lower part 3 of this nut is made in the form of a hollow cylinder with screw-threads on its inside, as shown at 0 on Fig. 5. These screwthreads are interrupted, as shown in Fig. 5, and there are two sets of screw-threads located opposite to each other and each set extending about a quarter. way around the interior of the hollow cylinder 3. The other part of the nut consists of a hollow cylinder 2, the lower part of which is reduced and fits into an enlarged portion in the cylinder 8, as shown in Figs. 4 and 5. The outer portion of the part 2 is provided at intervals with radially extending pins 0, against which the pin 0; is adapted to strike at intervals, as hereinafter described.

The lower interior portion of the part 2 is provided with interrupted screw-threads, there being two setsof these screwthreads located opposite each other and extending about a quarter of the way around the in terior of the part 2. The part 2 of the nut 'is provided with a slot 5 and the part 3 is provided with a pin 0, which enters the slot 6 allowing a slight degree of relative motion between these parts, but, under other conditions, compelling the two parts to rotate together.

The upper face of the part 2 is provided with a circular race way (1', in which are mounted antifriction balls (P, which bear against a wearing plate 4Z resting against the under part of the ring 0 The twopart feed nut, therefore, entirely surrounds the spindle it, being confined in position by the gear wheel rbelow, and the plate (1 above. Ordinarily the rotation of the gear wheel 1", upon the central portion on which thepart ,3 rests, causes the part 3 of the two part feed nut to move by friction, the part The beveled gear wheel" is'desired to bore the hole, and the part turned until the whole device is tightly hel in position, the boss 9 at one end and the pointed ends 9 at the other end holding the device firmly. The spindle u is then rotated by a brace, or in any desired manner, and this rotates the gear wheel 6, which drives the gear wheel 1', which in turn drives the spindle h, which is splined to said gear wheel, turning the bit q and commencing to bore a hole. The tooth a on the spindle u once during every revolution of the said spindle strikes against one of the teeth 6 on the part 2, forcing it in the opposite direction to which the part 3 is moved by the gear wheel 1". This feeds the bit 9 forward slightly, the parts 2 and 3 then revolving to gether until another of the pins 6 is struck by the part a. This relative motion of the two parts 2 and 3 is permitted by reason of the slot 6 in which the pin 0 engages, as already described. hen it is desired to bore a hole deeper than the length of the feed, the sleeve 79 is partially unscrewed, and by hand the lower part 3 of the two-part feed nut is turned until the screw threads in the two different parts register as shown in Figs. 5 and 10. In this position, the screw-threads in the feed and return nut are disengaged from the screw-threads on the spindle, so that the latter can be slid back into its original position in the device, as shown in Fig. 2, the spring a' meantime keeping the bit in engagement with the joist or other part in which a hole is being bored. The sleeve 7) is then tightened, the two parts of the feed nut adjusted into the position shown in Fig. 4, and the operation is repeated.

In Fig. 11, a modified form of the frame is shown. This modification is intended to be used in situations where it is necessary to apply the power at a different angle from that shown in Figs. 1 and 2. In this modification, the ring Z) is elongated. It is provided with a pin 4 and lower down with a groove 5. 6 represents a sleeve within which the ring or sleeve Z2 fits, and which is provided with a series of screws 7, passing through said sleeve and into the groove 5, the screws 7 being carried by the legs 9, which are preferably made integral with the sleeve 6. By this construction, the sleeve 7) is permitted to rotate freely within the sleeve 6, but said sleeve 6 is provided with semi-circular depressions 8 into any one of which the pin 4 may fit, locking the two sleeves together. After the device has been adjusted in position, the sleeve f is turned, forcing the pin 4 into one of the depressions 8 and locking the device in position, and then power is applied to the spindle u for the purpose of boring a hole, as above described.

I claim 1. In a boring device, the combination of a supporting frame, a bit, and feed mechanism therefor, including a two-part feed nut, a spindle carrying said bit and engaged by said nut, and means for rotating said spindle and means reversing the motion of one part of said nut at intervals, substantially as described.

2. In a boring device, feed mechanism therefor, consisting of a spindle having screw-threads on its outside, a two-part feed nut having partial internal screw-threads on both parts, means for operating said nut to feed the spindle, said operating means being provided with devices for reversing the motion of one part of the feed nut, substantially as described.

3. In a boring device, the combination of a supporting frame, a hollow spindle carried thereby, said spindle having partial screwthreads on its outside, a bit carried by said spindle, a two-part feed nut provided with partial screw-threads on its inside and surrounding and engaging said spindle, and means for operating said nut to feed said spindle, substantially as described.

4. In a boring device, the combination of a supporting frame, a hollow gear wheel supported in said frame, a two-part feed nut, having partial internal SC1\ -t-hreads, mounted between said gear wheel and a partof the frame, a spindle provided with partial external screw threads and located within said nut, a chuck carried by said spindle, a bit engaged by said chuck, and means for revolving said gear wheel, thereby operating said spindle, said operating means and one part of said feed nut being provided with devices for reversing the motion of part of said feed nut at intervals, substantially as described.

5. In a boring device, the combination of a supporting frame, a hollow gear wheel carried thereby, a feed nut composed of two parts, movable with respect to each other, and each provided with partial internal screw-threads, a hollow spindle closed at one end and provided with partial external screwthreads, a bit, a chuck carried by said spindle for holding said bit, a movable collet, a spring located inside of said spindle and adapted to move said collet, and driving means for operating said gear wheel and said nut, substantially as described.

' scribed.

7 In a boring device, the combination of a supporting frame, a hollow gear wheel mounted in said frame, a two-part feed nut between said wheel and a part of said frame,

antifriction devices between said frame and one of the parts of said nut, both parts of said nut being provided with partial internal screw-threads, and one part of said nut being provided with projecting pins, a hollow spindle, closed at one end and provided with partial external screw-threads, located within said nut, a bit carried by said spindle, and means for operating said gear wheel, including a gear wheel engaging with said first named gear wheel, and a projecting pin adapted to strike one of the pins on said nut at intervals, substantially as described.

8. In a boring device, the combination of a supporting frame, a gear wheel mounted on said frame, a two-part feed nut supported between said gear wheel and a part of said frame, a hollow spindle, closed at one end, and connected to said gear wheel so as to revolve therewith, a movable collet in said spindle, a spring normally tending to push said collet outof said spindle, a chuck carried by one end of said spindle, a bit adapted to have one end inserted in said collet and to be engaged by said chuck, and means for operating said gear wheel, including a gear wheel meshing with said first named gear wheel and provided with means adapted to control said feed nut, substantially as de scribed.

9. In a boring device, the combination of a supporting frame, a bit and feed mecha nism therefor, including a two-part feed nut, a spindle carrying said bit and engaged by said nut, and means for rotating said spindle and reversing the motion of part of said nut at intervals, said spindle being provided with means whereby said bit may be secured in different positions in said spindle, sub stantially as described.

In testimony, that I claim the foregoing as my invention I have hereunto set my hand this twenty-first day of July, A. D. 1905.

ELMER M. COBB. Signed in presence of:

GEO. E. BIRD,

A. G. BERRY. 

